It is well knwon to provide a housing for a wiring device or electrical connector which is to be used in an area exposed to weather wherein the housing has a pivotable or removable cover which, when closed, protects the electrical components in the housing from the weather but which can be opened for ready access to those electrical components.
Some such devices have hinged covers which are spring-urged toward a closed position so that they will remain open only while being manually held open or so held by a mating connector or similar device extending into the housing.
In addition, the cover and mouth of the housing can be provided with mating threads or cam surfaces so that the closed cover can be rotated to complete the weather seal.
If, when the cover is open, it is rotated to a position in which the cam surfaces or threads are not aligned to the proper position for commencing engagement, it is sometimes difficult to located the proper angular position from which the cover cam can be rotated into the fully locked condition. This is particularly true with cam surfaces which are normally not symmetrical. In an industrial or commercial environment, this commonly means that the worker who is supposed to close the cover becomes confused and does not rotate it into the locked position, thus failing to fully seal the structure into its weather-tight condition and partially defeating the purpose of the housing.
In addition, if the cover is rotated away from the proper position while open and is then allowed to snap shut by the spring force, the cams or threads can be damaged.
Following are several references which show housings and closures for electrical equipment and also rotatable closures from unrelated technical areas as examples of prior art structures related to the present invention.
______________________________________ U.S. Pat. No. 15,181 Hawkins U.S. Pat. No. 1,334,172 Ryerson U.S. Pat. No. 1,565,645 Hills U.S. Pat. No. 1,912,277 Kaye U.S. Pat. No. 2,072,608 Smith U.S. Pat. No. 2,425,846 Trewren U.S. Pat. No. 2,452,922 Gonsett et al. U.S. Pat. No. 3,140,344 Slater et al. U.S. Pat. No. 3,950,055 Samuels et al. French Patent 1,148,418 Hainault French Patent 549,642 Granat British Patent 521,132 Graviner Mfg., Co. Ltd. ______________________________________
The patents to Hawkins, Hills, Kaye, Smith and Trewren are examples of closures for gun breeches, port lights and other structures, some of which have threads or cam surfaces but which do not deal with the foregoing problems.
The French patent to Hainault, the British patent to Graviner Mfg., Co., Ltd., and the U.S. patents to Ryerson, Gonsett et al., Slater et al. and Samuels et al. show covers for electrical wiring devices which are either spring urged toward a closed position, are rotatable or are locked closed by separate means, but which do not treat the problem of rotation while open.
The French patent to Granat shows a rotatable cover for an electrical connector which is spring urged toward its closed position and which is rotatable to cause engagement of cams on the housing and cover to lock the cover closed. In addition Granat provides a ball detent on the hub of the cover to keep the cover properly positioned while open.
However, this structure has the disadvantage that it can easily be defeated by simply bumping the knob.